The present invention relates to lamp holders and relates more particularly to a lamp holder for a decorative string or Christmas tree light assembly which utilizes a switch to detect the connection of a lamp socket in each lamp holder in a decorative string or Christmas tree light assembly.
In a decorative string or Christmas tree light assembly, each lamp holder is made from a plastic tube having two opposite copper leaves respectively connected to an electric power supply by lead wires. Once the lamp socket of a lamp bulb is inserted in a lamp holder, the two conductors of the lamp socket contact the two copper leaves of the lamp holder, and therefore, the lamp bulb is electrically connected to emit light. Because the lamp holders of a decorative string or Christmas tree light assembly are connected in series, either lamp holder is disconnected or damaged, the whole electric circuit of the decorative string or Christmas tree light assembly becomes broken. Once the electric circuit of a decorative string or Christmas tree light assembly is broken, all the lamp holders must be checked one after another.